textproduct: Albany

WHAT HAS CHANGED

Similar to the previous forecast, adjusted minimum temperatures down slightly for tonight and included patchy fog due to favorable radiational cooling. Also, bumped up temperatures slightly for Monday, given expected full sunshine. With drier air mass moving into the region, we again leaned towards the lowered end of the blended guidance for dewpoints Monday and Tuesday afternoon to better represent the lower relative humidity values. Adjusted winds slightly higher for Tuesday afternoon again given deep mixing and tighter sfc gradient which looks to enhance the potential for fire spread.

KEY MESSAGES

1) Dry and seasonably warm today through Tuesday with breezier winds on Tuesday potentially enhancing fire weather concerns, depending on the state of the fuels.

2) Increasing confidence for widespread rain Wednesday night into Thursday but flooding impacts look unlikely. Then, temperatures trend cooler than normal late this week into the weekend.

DISCUSSION

KEY MESSAGE 1...

Sunny skies today and northerly winds advecting in a much drier air mass today will lead to relative humidity values falling to 25 to 35% across much of eastern NY and western New England. The highest RH values are in the mid-Hudson Valley and NW CT where clouds are taking longer to depart and where a widespread soaking rain fell yesterday. Then, upper level ridging builds eastward out of the Ohio Valley tonight into tomorrow before settling overhead by Tuesday resulting in large scale subsidence. Clear skies and radiational cooling tonight will likely allow temperatures to drop into the 30s by early tomorrow morning with patchy fog developing in valley areas. Any fog will quickly burn off tomorrow morning as abundant sunshine quickly allows deep boundary layer mixing to ensue leading to slightly above normal temperatures warming into the 60s and low 70s. The deep mixing and northwest dry air advection will easily allow dew points to drop during peak heating hours so we leaned towards the NBM10th percentile. While this will result in low relative humidity values dropping in the 30 to 40% range, light winds (under 10mph) should minimize fire weather concerns.

Another cool and clear night Monday night with morning sun on Tuesday mixing with gradually increasing clouds as our next moisture starved shortwave approaches. Deep boundary layer mixing will again occur during peak heating hours with south to southeast winds turning breezy (gusts up to 20-25mph). We again leaned towards the NBM10th percentile for dew points based on forecast soundings to showcase low relative humidity values again dropping 25 to 35% as afternoon high temperatures again warm into the 60s to low 70s. The combination of low RH values and breezier winds on Tuesday may result in an elevated risk for fire spread, depending on the state of the fuels. We will consult our fire weather partners to learn if fuels are available and if so, coordinate any Special Weather Statements to message the risk for near critical fire weather conditions and risk for fire spread.

KEY MESSAGE 2...

A moisture starved boundary and upper level trough approach late Tuesday into Tuesday night but weak overall forcing and moisture has capped POPs at slight chance to low end chance and limited to the western Adirondacks, northern/eastern Catskills and the western Mohawk Valley. Any showers that fall look very light as there is under a 10% for over a 0.10" of rain per latest NBM probabilistic guidance. While this rain will likely not saturate any available fuels, higher dew points and weaker winds on Wednesday should reduce fire weather concerns. Then, a trough over the Great Lakes amplifies on Wednesday as a shortwave rounds its base and strengthens as it tracks towards the Northeast Wed P.M into Wednesday night. Much stronger height falls and forcing for ascent combined with a moisture fetch out of the Gulf and western Atlantic look to support secondary cyclogenesis and a resulting coastal low off the mid- Atlantic coast Wed night into Thursday. There is increasing confidence that this will result in a widespread area of rain that sweeps across eastern NY and western New England Wed night into Thursday. In fact, the latest probabilistic guidance shows a 50 to 65% chance for at least a 0.50" of rain falling between 7pm Wed and 7pm Thurs regionwide; however, given antecedent dry conditions, flooding impacts appear unlikely. Should the coastal low deepen as it tracks into eastern New England, rainfall amounts will likely trend upwards as rain slows down and lingers longer into Thursday. Should the coastal low remain weak, rain amounts will likely be lower and the second half of Thursday should trend drier.

After this coastal low departs late in the week, much cooler air tracks into the Northeast with a trend towards below normal temperatures likely for the first weekend of May. With the growing season beginning May 1 in the Hudson Valley, southern Taconics and NW CT, we will remain vigilant for the potential for frost/freeze concerns.

AVIATION /18Z SUNDAY THROUGH FRIDAY/

Through 18z Monday...VFR conditions prevail across all terminals this afternoon as high pressure builds into the region. The resulting clearing trend will therefore yield clear skies by this evening and into tomorrow with light, variable winds. The only chance for conditions to deviate from the favored VFR category will be in the event that POU develops some mist/fog early tomorrow morning before sunrise. Winds are expected to become southerly there for a brief period early tomorrow morning and with prime radiational cooling conditions after a wet day yesterday, it certainly is a non-zero probability that at least MVFR visibilities result. Will provide additional updates in future iterations as confidence increases.

Outlook...

Monday Night: No Operational Impact. NO SIG WX. Tuesday: Low Operational Impact. Breezy. NO SIG WX. Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: Moderate Operational Impact. Chance of SHRA. Wednesday Night: High Operational Impact. Definite RA. Thursday: High Operational Impact. Likely SHRA. Thursday Night: Moderate Operational Impact. Chance of SHRA. Friday: Moderate Operational Impact. Breezy. Chance of SHRA.

ALY WATCHES/WARNINGS/ADVISORIES

CT...None. NY...None. MA...None. VT...None.